caudec is a command-line utility for GNU/Linux and OS X that transcodes (converts) audio files from one format (codec) to another. It leverages multi-core CPUs with lots of RAM by using a ramdisk, and running multiple processes concurrently (one per file and per codec). It is Free Software, licensed under the GNU General Public License (version 3). The APEv2 tagger that's bundled with versions 1.7.1 and later, is licensed under the Mozilla Public License, version 2.

Support for high quality resampling and downmixing / upmixing to stereo, with SoX.

Optimized I/O: input files are copied onto a tmpfs mount sequentially, so as to get the best performance out of the underlying medium (e.g. a hard drive). Transcoding however is done concurrently. Example: file 1 gets copied. When that's done, transcoding of file 1 starts. Meanwhile, file 2 gets copied, etc… Very little time is lost reading the files.

Transcoding to several different codecs at once is possible. In that case, decoding of input files is done only once.

Multiple instances of caudec can be run concurrently while sharing ressources.

Metadata is preserved (as much as possible) from one codec to another.

Multiprocess Replaygain scanner (except for Opus and Musepack).

Uses existing, popular command line encoders/decoders.

Tested under Arch Linux and OS X. Download here. Please use the bug tracker to report any bugs. Feedback is most welcome!

The encoder/decoder (Takc.exe) works with wine. Linux users can use it for archiving, while transcoding to some other codec (e.g. lossy) for listening purposes. Caudec supports TAK encoding and decoding if the user has installed both Wine and TAK.